Related papers: Fine structures in the atmosphere above a sunspot …
Recent observations of sunspot light-bridges have shed new light on the fact that they are often associated with significant chromospheric activity. In particular chromospheric jets (Shimizu et al. 2009) persisting over a period of days…
We study the velocity field of umbral dots at a resolution of 0.14". Our analysis is based on full Stokes spectropolarimetric measurements of a pore taken with the CRISP instrument at the Swedish 1-m Solar Telescope. We determine the flow…
The Solar Optical Telescope (SOT) aboard HINODE successfully and continuously observed a formation process of a light bridge in a matured sunspot of the NOAA active region 10923 for several days with high spatial resolution. During its…
We present and discuss multi-wavelength observations of five homologous recurrent solar jets that occurred in active region NOAA 11133 on 11 December, 2010. These jets were well observed by the Solar Dynamic observatory (SDO) with high…
We report a chromospheric jet lasting for more than 1 hr observed by Hinode Solar Optical Telescope in unprecedented detail. The ejection occurred in three episodes separated by 12-14 min, with the amount and velocity of material decreasing…
The solar atmosphere is full of complicated transients manifesting the reconfiguration of solar magnetic field and plasma. Solar jets represent collimated, beam-like plasma ejections; they are ubiquitous in the solar atmosphere and…
Time series of high-resolution images of the complex active region NOAA 10786 are studied. The observations were performed in G-band (430.5 nm) and in the nearby continuum (463.3 nm), on July 9, 2005 at the Swedish 1-meter Solar Telecope…
Umbral dots (UDs) are transient, bright features observed in the umbral region of a sunspot. We study the physical properties of UDs observed in sunspots of different sizes. The aim of our study is to relate the physical properties of…
Penumbral microjets (PJs) are transient narrow bright features in the chromosphere of sunspot penumbrae, first characterized by Katsukawa et al (2007) using the \CaII\ H-line filter on {\it Hinode}'s Solar Optical Telescope (SOT). It was…
Sunspot light bridges are known to exhibit a variety of dynamic and persistent phenomena such as surges, small-scale jets etc. in the chromosphere and transition region. While it has generally been proposed that magnetic reconnection is…
We investigate the dependence of penumbral microjets inclination on the position within penumbra. The high cadence observations taken on 10 November 2006 with the Hinode satellite through the \ion{Ca}{ii} H and G--band filters were analysed…
Solar activity is controlled by the magnetic field, which also causes the variability of the solar irradiance that in turn is thought to influence the climate on Earth. The magnetic field manifests itself in the form of structures of…
We report the bi-directional moving structures in a coronal bright point (CBP) on 2015 July 14. It is observed by the Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). This CBP has a lifetime of about 10 minutes,…
The solar chromosphere hosts a wide variety of transients, including dynamic fibrils (DFs) that are characterised as elongated, jet-like features seen in active regions, often through H$\alpha$ diagnostics. So far, these features have been…
In sunspot umbrae, the core of some chromospheric lines exhibits periodic brightness enhancements known as umbral flashes. The consensus is that they are produced by the upward propagation of shock waves. This view has recently been…
We study the formation of a sunspot penumbra in the active region NOAA11024. We simultaneously observed the Stokes parameters of the photospheric iron lines at 1089.6 nm with the TIP and 617.3 nm with the GFPI spectropolarimeters along with…
Context : Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields. Aims : We study the formation of a penumbra in a decaying sunspot and compare its…
Employing the high spatio-temporal Interface Region Imaging Spectrograph 1330 {\AA} observations, we investigated the jet-like features that occurred during the X8.2 class flare in NOAA active region (AR) 12673 on 2017 September 10. These…
We report on a fan-shaped set of high-speed jets above a strongly magnetized light bridge (LB) of a sunspot observed in the H$\alpha$ line. We study the origin, dynamics and thermal properties of the jets using high-resolution imaging…
We report on observations of a solar jet propagating along coronal loops taken by the Solar Dynamics Observatory (SDO), the Interface Region Imaging Spectragraph (IRIS) and 1-m New Vacuum Solar Telescope (NVST). The ejecta of the jet…